French challenger Byword gave 21-year-old jockey Maxime Guyon a dream Royal Ascot debut Wednesday to land the Prince of Wales' Stakes from British defender Twice Over who battled in vain to peg back the fast improving colt. The trainer of Byword, narrowly beaten by champion filly Goldikova on his last outing in Paris, confessed he was only worried about the relative inexperience of his young jockey. Those fears were unfounded. Fabre, who trained Manduro to win the race in 2007, said: “The horse had the ability to win. I was a bit worried about an inexperienced jockey but he had a perfect ride.” Guyon, grinning from ear to ear after his debut at one of the world's most famous racecourses, said through an interpreter: “I am delighted to be given the opportunity. I cannot thank Mr. Fabre enough.” The colt's owner was on the mark again in the last race of the day when Tom Queally booted home Timepiece to give trainer Henry Cecil a phenomenal 72nd Royal Ascot success. Earlier, Rainfall handed champion jockey Ryan Moore his first triumph at Royal Ascot 2010 with a hard fought victory over Red Jazz in the opening Jersey Stakes. The lightly-raced filly broke the course record over seven furlongs (1.4 km) with a blisteringly fast run. For trainer Mark Johnston it was his 31st winner at Britain's top flat race meeting of the year. Resplendent in tartan trousers to accompany his top hat and tails, the prolific Scottish trainer told reporters: “Rainfall is very, very straightforward, such an honest filly to train. She couldn't be easier.” Just over half-an-hour later, Moore was back in the winner's enclosure after holding on to land the Windsor Forest Stakes for fillies on Strawberrydaiquiri (9-2) in a tremendous tussle with Johnny Murtagh on last year's winner Spacious. Strawberrydaiquiri prevailed by a short head to open this year's Royal Ascot account for Derby-winning trainer Michael Stoute who was full of praise for Moore's forceful ride. Frankie Dettori was another to break his Royal Ascot duck for the meeting after steering an outsider Invisible Man to victory for Dubai's Godolphin outfit in the Royal Hunt Cup, one of the most competitive handicaps of the year. Day three of the royal meeting Thursday, known as Ladies' Day, features the Group One Ascot Gold Cup.